Household solid waste currently ends up in land fills or is burned in an incinerator in what is commonly known as an energy-from-waste (EFW) process. While many municipalities have recycling facilities to capture certain mainstream recyclable plastics, such as polyethylene terephthalate (recycle code 1) and high density polyethylene (HDPE, recycle code 2), other plastics that are not considered to be mainstream recyclable plastics (recycle codes 3-7) end up with the rest of the municipal solid waste. Burning plastics that contain carbon releases carbon dioxide.
It is estimated that plastics comprise 16% of waste discards, yet account for 66% of CO2 emissions from EFW processes. EFW processes currently dispose of about 20% of the waste stream. It is desirable to isolate and sequester post-consumer plastic discards that are currently going to landfills and incinerators, so that CO2 emissions may be reduced, and the carbon contained in the plastics may be used in a durable building material, rather than sit in a landfill.